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Unformatted text preview: opper and Cobalt ions are amongst the most hazardous inorganic pollutants present in heavy metal –laden water systems, and are often as a result of extensive and wild applications of mining, petroleum refining, electroplating, textile industry etc. The presence of these cationic species in aquatic ecosystems results in their accumulation in living organisms, thereby causing several adverse effects, hence the remediation, treatment and removal of heavy metal ions from water has become a major concern for many process industries. In this study, ethylene vinyl acetate (EVA), a copolymer of ethylene and vinyl acetate has been mixed with clinoptilolite (C) as the filler, to prepare EVA -C nanocomposites. Although it is non biodegradable EVA is an inert, hydrophilic polymer with excellent cohesive strength and adhesion to a wide range of substrates. Incorporation of the clinoptilolite, with its high mechanical and chemical resistance, into the binding polymer yields an effective adsorbent and ion exchange medium that has the potential to combine the advantages of both while eliminating their shortcomings, for application in wastewater treatment. EVA-C nanomposites were prepared by the melt mixing technique in a rheomixer (Haake Rheomex OS) and the strips were extruded through a single screw extruder at 120 °C and a speed of 60 rpm for 30 minutes. The films were then characterised with SEMEDS, XRD and FTIR. Heavy metal removal capacity was investigated using the batch technique as a function of pH, contact time, filler dosage and initial concentration of solutions. To investigate the influence of pre-treatment, the composites were subjected to KCl, NaCl as well as HCl activation. Sorption mechanisms of the metal ions in single and mixed solutions were also evaluated. Res ults show that equilibrium was reached after 24 hours, and that sorption was maximum at between pH 5 and 7. The selectivity series was observed to be Pb >Cu >Co, and was consistent in both single and mixed solutions. Pretreatment was observe to significantly increase adsorption capacity,...
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- Spring '11